Dear TSA: This Is Why You Shouldn’t Post Pictures Of Your Keys Online

September 18, 2015 by 121 Comments

We have to hand it to the Transportation Security Administration (TSA). They seem to have a perfect track record of screwing up – and that’s not an easy thing to accomplish if you think about it. If it’s not reports of TSA agents stealing valuables or inappropriately groping passengers, there is the fun fact that in all the years since it was created in 2001, the agency hasn’t caught a single person seeking to do harm in the friendly skies. We’re actually okay with that if it means nobody is trying to do anything shady.

The most recent TSA folly seemed to practically fall into the Internet’s lap when a reporter for the The Washington Post published a hi-res picture of the entire set of TSA master keys while writing an article about how the TSA handles your bags after checking them at the counter. Well, the lock picking community when nuts and in a short time had 3D printed versions available and working. You can see it in action in the (twitter) video after the break.

For those that are not familiar with travel in the US, you are not allowed to use just any old lock on your bags. It has to be approved by the TSA – and that means that they have to be able to open it. So the TSA agents have a set of master keys that can open any bag if they need to look inside for some reason. If you put a non-TSA approved lock on the bag, that can make them a little angry, and you risk having your bag delayed or even cut open.

Of course, you can get into just about any suitcase with a ball point pen, so maybe this isn’t a real “security” issue, but it sure isn’t what you want to see from the agency that is supposed to protect you. Who knew that you could make keys from a photograph? We did way back in 2009 and way more in depth this May… maybe the TSA should start reading Hackaday?

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Embed With Elliot: Interrupts, The Good…

September 18, 2015 by 32 Comments

What’s the biggest difference between writing code for your big computer and a microcontroller? OK, the memory and limited resources, sure. But we were thinking more about the need to directly interface with hardware. And for that purpose, one of the most useful, and naturally also dangerous, tools in your embedded toolchest is the interrupt.

Interrupts do exactly what it sounds like they do — they interrupt the normal flow of your program’s operation when something happens — and run another chunk of code (an interrupt service routine, or ISR) instead. When the ISR is done, the microcontroller picks up exactly where it left off in your main flow.

Say you’ve tied your microcontroller to an accelerometer, and that accelerometer has a “data ready” pin that is set high when it has a new sample ready to read. You can wire that pin to an input on the microcontroller that’s interrupt-capable, write an ISR to handle the accelerometer data, and configure the microcontroller’s interrupt system to run that code when the accelerometer has new data ready. And from then on everything accelerometer-related happens automagically! (In theory.)

This is the first part of a three-part series: Interrupts, the Good, the Bad, and the Ugly. In this column, we’ll focus on how interrupts work and how to get the most out of them: The Good. The second column will deal with the hazards of heavyweight interrupt routines, priority mismatches, and main loop starvation: the Bad side of interrupts. Finally, we’ll cover some of the downright tricky bugs that can crop up when using interrupts, mainly due to a failure of atomicity, that can result in logical failures and corrupted data; that’s certainly Ugly.

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Golden Commodore C64 Brings The Bling To 8-Bit Computing

September 18, 2015 by 9 Comments

Sometimes, a hack is just a hack. And sometimes, a hack is nothing but a gold-plated Commodore C64.

Alright, it’s not gold-plated, it’s gilded. For the uninitiated, gilding is the process of gluing gold powder or gold leaf to an object. Gold is amazingly ductile – a tiny nugget 5mm in diameter can be hammered into a sheet of gold leaf that can cover about a half a square meter. It’s extremely thin and delicate and has to be handled very gingerly, and the gilder’s craft is therefore very meticulous. For more on gilding, see this post on signmaking with gold leaf.

[thefuturewas8bit], who runs a vintage Commodore web store, did a great job gilding a C64 case, just because. The attention to detail is fantastic – notice that even the edges of the keyboard cutouts are gilded and burnished. A nice finishing touch is swapping out the stock red power LED for a yellow one – red simply clashes too much. Lest you think there’s nothing to learn from a purely aesthetic hack, [thefuturewas8bit] shares a great tip for removing the metal badges from a plastic case – spray them with freeze-spray from the back to pop off the glue. No need to dig at them with a screwdriver and gouge or bend them. Nice trick.

Any hack can earn extra points for style, and we think that gold works well on the C64.  But if gold is a little too overstated for you, you can always try to score a colorful new injection-molded case for your vintage Commodore.

Introducing The Nintendo Guitar Boy

September 18, 2015 by 10 Comments

Need to thrash out some wicked 8-bit riffs? There’s only one guitar you should be doing that with, and it’s a Guitar Boy!

[Fibbef], an administrator on BitFixGaming boards built this as an exhibition piece for his 2015 Game Boy Classic build off. He started the build just three months ago and we have to say we’re impressed. It’s a fully functioning Raspberry Pi Game Boy emulator — and a full fledged electric guitar. The A and B buttons double as volume and tone dials for the guitar, while also being push buttons for the Game Boy!

Under the hood is a Raspberry Pi B+ running RetroPie v2.3, with a 5″ LCD display, custom wooden buttons, the entire body is hand made, and a plexiglass shell covers the whole thing.

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Hackaday Prize Semifinalist: Walking Robots From Scratch

September 17, 2015 by 7 Comments

The usual way robotics is taught – and nearly everything, for that matter – is simple. A teacher gets a pre-built module or kit, teaches the students how to use the kit, and class is adjourned. There are significant and obvious drawbacks to this. [Kevin Harrington]’s entry for the Hackaday Prize turns that pedagogy on its head. It’s a robotics development platform that encourages everyone to create their own robots from scratch, starting with the question, ‘how many legs do you want your robot to have’.

Bowler Studio uses OpenCV for image processing, a kinematics engine, a JCSG-based CAD and 3D modeling engine to interface with motors, create 3D models according to kinematic models, feed imaging data to a robot, and create graphical interfaces for robots. It’s an entire robotics creation studio in a single package, and of course everything can be backed up to the cloud.

The electronic backbone is another one of [Kevin] and Neuron Robotics’ projects, DyIO, a USB peripheral that makes for a great robotics platform. The DyIO can control up to 24 servos, enough for a very, very complex robot, and also has the ability to control motors, read encoders, or just blink pins.

These two projects together make for a great way to learn the ins and outs of robots that are a little more complex than a simple wheeled robot, and expandable enough to make some really, really cool projects

The 2015 Hackaday Prize is sponsored by:

There’s A Bug In My Robot

September 17, 2015 by 15 Comments

What has six legs, 25 LEDs, a Microchip CPU, can be sewn into clothing, and even plugged into a Raspberry Pi? The answer, it turns out, is the CodeBug–a low cost computer board aimed at the educational market. These board were crowdfunded and are now available for general purchase. [Mike Redrobe] took one of the boards, connected a few servos and used the CodeBug’s Scratch-like language to create a small robot.

You can see the robot in the video below. Programs download via USB (the board looks like a USB drive). You can also send commands over USB to operate in tether mode, or you can directly plug the board into a Raspberry Pi.

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Circular Saw + Innovative Fence = Unique DIY Table Saw

September 17, 2015 by 26 Comments

A table saw is often the first machine the aspiring woodworker wants for the shop. But even a lightweight contractor’s saw is not cheap, and a really good cabinet saw is both expensive and incredibly heavy. And any table saw is an intimidating machine that can liberate your fingers from your hand in a trice. Looking for a solution to all of these problems, [Seumas] has come up with a unique table saw conversion for a circular saw that improves safety and lowers the barrier to table saw ownership.

Flipping a low-cost circular saw upside down and attaching it to a table is old hat – we’ve seen plenty of examples of that before, including this recent post. Where [Seumas]’s idea shines is in the integration of the fence and the table. A typical fence needs to stay perfectly parallel to the blade while being dead square to the table, but still needs to be moved to adjust the width of cut. In [Seumas]’s design, the fence is fixed to the table, and the whole table slides left and right on high-pressure laminate rails. In theory, the fence will never go out of true, and the width of cut can be a lot wider than the typical table saw – an impressive 3 feet to the right of the blade.

As for safety, [Seumas] shows off quite a selection of DIY attachments in the video after the break. He builds his own Lexan blade guard, anti-kickback pawls, and stock hold-downs. Add in the little touches like shop-made clamps for locking the table, extending outfeed support, and built-in dust collection, and you can make yourself a pretty capable machine at the fraction of the cost of buying.

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